A new method for rapidly determining total antioxidant capacity (TAC) in a biological sample has been devised and evaluated. A surfactant present in the reagent causes the lysis of cells in the sample. Glutathione, as...A new method for rapidly determining total antioxidant capacity (TAC) in a biological sample has been devised and evaluated. A surfactant present in the reagent causes the lysis of cells in the sample. Glutathione, ascorbic acid, protein thiols and other main reducing substances in the sample react with a specific redox chromogen (2,6-dichlorophenolindophenol) and produce a change in the color of the reagent, which is determined photometrically at 630 nm. This new method quantifies the overall capacity of the sample to reduce a redox chromogen and it requires the minimum volumes and time. The assay can be used on a wide variety of biological samples including whole blood, serum, plasma, tissue extracts and homogenates, food, wine, fruit juice and other beverages. Results are expressed in terms of mmol/L glutathione equivalents. TAC can be assayed manually, on automatic analyzers or micro-plate readers.展开更多
Two new 2-substituted thiazolidine-4（R）-carboxylic acids （TCAs）, 2-glusosaminal-TCA （GIcNH2Cys） and 2-N-acetyl-glueosanlinal-TCA （GlcNAeCys）, were synthesized. Their protective effects against liver toxicity i...Two new 2-substituted thiazolidine-4（R）-carboxylic acids （TCAs）, 2-glusosaminal-TCA （GIcNH2Cys） and 2-N-acetyl-glueosanlinal-TCA （GlcNAeCys）, were synthesized. Their protective effects against liver toxicity induced by acetaminophen （APAP） were investigated in a mice model. The resuits demonstrate that administration of TCAs （ i. p. , 800 mg/kg） 30 min after APAP challenge efficiently decrease ALF, AST, and LDH levels in liver. GlcNAcCys shows the best proteetive eftects, decreasing ALT, AST and LDH levels to 63%, 18.4% and 37% of the APAP group respectively. Comparison with the control showed that APAP greatly decreases total sulfhydlyl （T-SH） levels （43%）, non-protein hound sulfhydryl （NP-SH） levels （50%） and total antioxidative capabilities （57%） in the liver 24 hr after challenge. TCAs treatments 30min after APAP challenge significantly elevate sulfhydryl levels and total antioxidative capabilities. APAP administration also markedly （P 〈 0.05） increases liver lipid peroxidation to 1.65 and 1.17 times that of the control 4 hr and 24 hr after APAP administration respectively. TCAs treatments can inhibit lipid peroxidation as measured by decreased malondialdehyde （MDA） contents in liver. The histopathological results also further confirm the hepatoprotective effects of TCAs. In conclusion, our data show that TCAs, GleNAcCys particularly, have hepatoprotective anti antioxidant etfects.展开更多
文摘A new method for rapidly determining total antioxidant capacity (TAC) in a biological sample has been devised and evaluated. A surfactant present in the reagent causes the lysis of cells in the sample. Glutathione, ascorbic acid, protein thiols and other main reducing substances in the sample react with a specific redox chromogen (2,6-dichlorophenolindophenol) and produce a change in the color of the reagent, which is determined photometrically at 630 nm. This new method quantifies the overall capacity of the sample to reduce a redox chromogen and it requires the minimum volumes and time. The assay can be used on a wide variety of biological samples including whole blood, serum, plasma, tissue extracts and homogenates, food, wine, fruit juice and other beverages. Results are expressed in terms of mmol/L glutathione equivalents. TAC can be assayed manually, on automatic analyzers or micro-plate readers.
文摘目的探讨氧化应激及炎性反应指标在缺血性脑卒中的临床意义。方法检测缺血性脑卒中(ischemic stroke,IS)患者和健康对照组血清中总抗氧化能力(total antioxidant capacity,TAC)、氧化型低密度脂蛋白(oxidized low density lipoprotein,Ox-LDL)、超氧化物歧化酶(super oxide dismutase,SOD)、超敏C反应蛋白(high sensitivity C reactive protein,Hs-CRP)等指标的表达,采用ELISA方法检测血清TAC、Ox-LDL;在贝克曼库尔特AU5821全自动生化分析仪上检测其他指标的水平。结果 (1)治疗组较正常对照组血清中TAC显著性降低,几乎为健康人水平的1/12(P<0.01),高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、SOD的水平有所下降(P<0.05);(2)Hs-CRP、Ox-LDL、低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)的水平显著性升高(均P<0.01),治疗组血清中Hs-CRP约为对照组的16倍,其OX-LDL水平约为1.7倍,LDL-C约为1.6倍。治疗组较对照组血清中氧化应激及炎性反应指标的表达差异有统计学意义。结论脑卒中的发生可能与氧化应激、炎性反应有重大关系。
文摘Two new 2-substituted thiazolidine-4（R）-carboxylic acids （TCAs）, 2-glusosaminal-TCA （GIcNH2Cys） and 2-N-acetyl-glueosanlinal-TCA （GlcNAeCys）, were synthesized. Their protective effects against liver toxicity induced by acetaminophen （APAP） were investigated in a mice model. The resuits demonstrate that administration of TCAs （ i. p. , 800 mg/kg） 30 min after APAP challenge efficiently decrease ALF, AST, and LDH levels in liver. GlcNAcCys shows the best proteetive eftects, decreasing ALT, AST and LDH levels to 63%, 18.4% and 37% of the APAP group respectively. Comparison with the control showed that APAP greatly decreases total sulfhydlyl （T-SH） levels （43%）, non-protein hound sulfhydryl （NP-SH） levels （50%） and total antioxidative capabilities （57%） in the liver 24 hr after challenge. TCAs treatments 30min after APAP challenge significantly elevate sulfhydryl levels and total antioxidative capabilities. APAP administration also markedly （P 〈 0.05） increases liver lipid peroxidation to 1.65 and 1.17 times that of the control 4 hr and 24 hr after APAP administration respectively. TCAs treatments can inhibit lipid peroxidation as measured by decreased malondialdehyde （MDA） contents in liver. The histopathological results also further confirm the hepatoprotective effects of TCAs. In conclusion, our data show that TCAs, GleNAcCys particularly, have hepatoprotective anti antioxidant etfects.
